1. Field of the Invention
The present invention relates to an ink jet cartridge and a manufacturing method of the ink jet cartridge in which a fiber absorber is accommodated, wherein the fiber absorber is configured of a fiber aggregate in which a crossing point is unwelded, specifically, to the ink jet cartridge and the manufacturing method of the ink jet cartridge that improves a disadvantage or the like of the ink charging operation.
2. Description of the Related Art
An ink jet recording apparatus includes an ink jet recording head in which ink is discharged and an image is drawn, and an ink tank that accumulates ink that is supplied to the recording head. An ink tank is known in which an ink absorber is accommodated as a configuration of retaining ink. As the ink absorber, a fiber absorber that is formed of fiber aggregate or foam, such as urethane sponge is present. As one example of the fiber absorber, a felt fiber absorber is disclosed in Japanese Patent Application Laid-Open No. H06-255121. The felt fiber absorber is easy to adjust for appropriate fiber diameter, fiber length, arrangement direction or the like, and easy to adjust for storage ability of ink or supply ability of ink. Also, a material that is chemically stable with respect to ink can be selected.
As described above, the fiber absorber shows a high ability as the ink absorber, however destruction may be generated by external stress even though freedom of shape is present since the shape of the fiber absorber is determined by tangling of the fiber. Thus, there is a case whereby, for example, an air layer is generated at a connection section that is connected to an ink supply tube that is connected to an ink flow path, an adjustment of the density fails, and then the retention ability of ink or the supply ability of ink is affected. Further, in the fiber absorber, since many fiber ends become fluffy and project from the surface of the absorber, it is necessary to improve workability when the fiber absorber is filled within the ink tank and a lid covers the ink tank.
In Japanese Patent Application Laid-Open No. H07-047688, a technique is suggested, in which a change in the external shape is suppressed and lowering of the retention ability of ink or the supply ability of ink is suppressed by melting the surface of the fiber absorber.
Also, as a configuration of fiber aggregate, Japanese Patent Application Laid-Open No. H09-183236 discloses fiber of a core-clad structure in which polypropylene is arranged at a core section and polyethylene is arranged at a clad section. In the related art, a technique is disclosed in which only polyethylene is melted, and the crossing point of the fiber is welded using the difference between the melting points of the materials in the fiber aggregate so that shape maintenance and stiffness of the ink absorber are maintained. Further, a configuration is also disclosed in which the periphery of the fiber aggregate is thermoformed by heating and then an ink absorber is obtained which is suitable for the interior shape of the case of an ink tank.
As described above, an example an ink filling method with respect to the ink tank in which the fiber absorber of which the surface is melted is accommodated is disclosed in Japanese Patent Application Laid-Open No. 2000-000976. According to Japanese Patent Application Laid-Open No. 2000-000976, a technique is described in which ink is filled from the ink supply opening that is provided in the ink tank so as to supply ink to the ink jet recording head.
Meanwhile, an ink jet cartridge is disclosed in which the ink jet recording head and the ink tank are integrally configured. In the case of the ink jet cartridge, the ink jet recording head is already connected to the ink supply opening that is provided in the ink tank and when the method that is disclosed in Japanese Patent Application Laid-Open No. 2000-000976 is applied, ink is filled from an ink discharging port that is provided in the ink jet recording head. However, the ink discharging port of the ink jet recording head employs a configuration for discharging very small ink droplets and for example, the ink discharging port only has a diameter on the order of microns. Time is wasted on an operation where ink is charged from a very small port and adoption is difficult from the point of view of productivity. Also, when putting in to practice charging ink from the ink jet recording head side, there are many items to be considered.
While, Japanese Patent Application Laid-Open No. 2006-159656 discloses an example of a method of filling ink to the ink jet cartridge. In the publication, a fiber absorber is filled with respect to a case that has an opening in a surface opposite to the surface on which the ink jet recording head is arranged and a lid is welded over the opening so that the ink jet cartridge is manufactured. A configuration is disclosed in which an ink injection needle is inserted into an ink absorber from the opening and ink is injected before the lid is welded.
In the ink filling method that is disclosed in Japanese Patent Application Laid-Open No. 2006-159656, when the ink injection needle is pulled out from the ink absorber after ink is filled, friction force is generated between the ink absorber and the ink injection needle. In a case where the configuration is applied in points where the fibers cross each other in the fiber aggregate are not melted as disclosed in Japanese Patent Application Laid-Open No. H06-255121, as an example configuration of the fiber absorber, the ink absorber is dragged by the ink injection needle. Thus the ink absorber may move toward the ink injection port side, in other words, in a direction opposite to the ink supply section (ink supply opening side), and the contact between the ink absorber and the ink supply opening may be weakened and the ink supply may be unstable.